We have a few facts that point towards his potential guilt, imo.
For one, his statements about the event do not seem credible. Hard to believe that he could see on the monitor, that his child was blue. That is very questionable.
And if he did see a blue child, even harder to believe that he didn't call 911 and/or scream loudly for help. He said nothing about trying to revive either child.
Sadly, I have known several parents who have found an unresponsive child or spouse. Trying to immediately REVIVE their loved one is the immediate priority. Calling 911, screaming for help from neighbors, doing CPR, would be his response, if he really saw a child sprawled on her bed, blue in the face. He didn't do anything of the sort.
His other child was in the process of being strangled. She had a great chance to be saved if he had tried to do so. But he said nothing about trying to save her. Instead, he spent precious long minutes strangling his wife, and thus killing his only surviving child in the process.
These facts point to his potential guilt, not his potential innocence, in my opinion.
Nothing in his story makes much sense. Why would they be having a deep emotional discussion 2 hours after she arrived home, from a long delayed flight. She was ill, pregnant and exhausted. She would have been asleep if she had her choice.
And he said he asked for a separation and she snapped. But our VI said he had asked for a separation repeatedly, with little response from her. Why would a pregnant woman, thrilled about the little boy she had already named, brutally slaughter her babies, over a proposed separation, that she knew about for weeks or months?